Weighted sporting goods, such as baseball bats, tennis racquets and the like, have been used for many years during practice swinging of such sporting goods. After practicing with a weighted device, the actual device will feel lighter and quicker in the hands when used during actual play. For example, in baseball the batter waiting in the on-deck circle calmly swings a weighted bat or several bats together. The most common type of weight used in the on-deck circle is a doughnut-shaped weight which is slipped over the handle end of the bat and is restrained at its inner periphery by the widened portion of the bat.
A similar device has been developed for golfers. For example, in U.S. Pat. No. 4,809,975, a golf club swing trainer for developing arm muscles is disclosed. The swing trainer includes a truncated golf club shaft and a weight slidably mounted on the shaft. A golf club handle is formed at one end of the shaft. At the other end of the shaft, a coil spring is coaxially mounted over the shaft. The spring provides a resistance on the weight as the weight swings toward the end of the shaft when the trainer is swung like a golf club. The sensation of increased torque from the centrifugal force causing the weight to move down the shaft can then be felt in the arm of the person using the device. With the use of such a practice device, one can learn the feel of a correct golf club swing.
A disadvantage and limitation of the device disclosed in the '975 patent is that the user does not have an actual golf club with a golf club head that allows him to also visually determine a proper arc of the golf club. Furthermore, the known prior art does not disclose any type of sports training device which combines the effect of using a fixed weight, such as on a bat, with a slidable weight as disclosed in the '975 patent.